1. Field of the Invention
The present invention relates to a lightguide and, more particularly, to a lightguide for flat panel display devices and method for manufacturing the lightguides.
2. Description of Related Art
Currently, lightguides are widely used in flat panel display device (e.g. liquid crystal display device) to distribute the light of backlight module. Generally, a backlight module includes a lightguide, a plurality of prism sheets and a plurality of diffuser sheets. However, since many sheets are required in the traditional backlight module, the thickness of traditional backlight module is great and hard to be reduced.
In recent years, in order to reduce the thickness of the traditional backlight module, a prismless backlight module is introduced to the flat panel display. However, the manufacturing processing of the components of the prismless backlight module is complicated. The surface of the lightguide is required to form a plurality of microlens. It takes long time to processing. Although this kind of lightguide can be made through inject molding, the cost for manufacturing molds is high. The time needs for manufacturing these kinds of molds is very long. In addition, the wearing of these kinds of molds is serious as they are used for mass-production. In other words, the lifetime of these molds for these lightguides is short. Therefore, these kinds of molds and lightguides are not suitable for being applied for mass-production.
Therefore, it is desirable to provide an improved speech recognition method to mitigate the aforementioned problems.
The object of the present invention is to provide a lightguide with low cost of material, low thickness and less weight.
Another object is to provide a lightguide having an additional function for diffusing or distributing light.
Another object is to provide a method for manufacturing a lightguide having an additional function for diffusing or distributing light.
Another object is to provide a method for manufacturing various lightguides with different patterns of prisms without cutting patterns of microlens on molds.
Another object is to provide a method for manufacturing various lightguides through simple inject molding.
To achieve the object, the lightguide of the present invention includes: a prism sheet having a plane surface and a surface with a plurality of patterned microlens; a transparent wedge having a cross-section of trapezoid; and a binder layer sandwiched between said plane surface of said prism sheet and said transparent wedge, wherein said binder and said prism sheet are made from substantially identical or different materials.
The laminated film of the present invention for manufacturing a lightguide, comprising: a carrier sheet; a prism sheet having a plane surface and a patterned surface with a plurality of microlens; a protection sheet sandwiched between said carrier sheet and said patterned surface of said prism sheet, wherein said protection sheet has a patterned surface to contact with said prism sheet, and the pattern of said patterned surface of said protection layer is complementary to the pattern of said prism, and a binder layer attached on said plane surface of said prism sheet; wherein said binder and said prism sheet are made from substantially identical or different materials.
Another laminated film of the present invention for manufacturing a lightguide, comprising: a carrier sheet; a prism sheet having a plane surface and a patterned surface with a plurality of microlens; a diffuser sheet sandwiched between said carrier sheet and said patterned surface of said prism sheet, wherein said diffuser sheet has a patterned surface to contact with said prism sheet, and the pattern of said patterned surface of said diffuser layer is complementary to the pattern of said prism; a protection sheet for protecting said prism sheet or said diffuser sheet, wherein said protection sheet is sandwiched between said carrier sheet and said diffuser sheet; a binder layer attached on said plane surface of said prism sheet; wherein said binder and said prism sheet are made from substantially identical or different materials.
The method of the present invention for manufacturing a lightguide, comprising following steps: (A) providing a mold having a laminated film inside, said laminated film comprising: a carrier sheet; a prism sheet having a plane surface and a patterned surface with a plurality of microlens; a protection sheet sandwiched between said carrier sheet and said patterned surface of said prism sheet, wherein said protection sheet has a patterned surface to contact with said prism sheet, and the pattern of said patterned surface of said protection layer is complementary to the pattern of said prism; and a binder layer attached on said plane surface of said prism sheet; (B) injecting a polymer into said mold with said laminated film, and said plane surface of said prism sheet is bonded to said injected polymer after the injection of said polymer; (C) opening said mold and taking out the molding; and (D) releasing said carrier sheet and said protection sheet from said molding.
Another method of the present invention for manufacturing a lightguide, comprising following steps: (A) providing a mold having a laminated film inside, said laminated film comprising: a carrier sheet; a prism sheet having a plane surface and a patterned surface with a plurality of microlens; a diffuser sheet sandwiched between said carrier sheet and said patterned surface of said prism sheet, wherein said diffuser sheet has a patterned surface to contact with said prism sheet, and the pattern of said patterned surface of said diffuser layer is complementary to the pattern of said prism; a protection sheet for protecting said prism sheet or said diffuser sheet, wherein said protection sheet is sandwiched between said carrier sheet and said diffuser sheet; a binder layer attached on said plane surface of said prism sheet; wherein said binder and said prism sheet are made from substantially identical or different materials; (B) injecting a polymer into said mold with said laminated film, and said plane surface of said prism sheet is bonded to said injected polymer after the injection of said polymer; (c)) opening said mold and taking out the molding; and (D) releasing said carrier sheet and said protection sheet from said molding.
Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.